JPEG XS is an upcoming standard from the JPEG Committee (formally known as ISO/IEC SC29 WG1). It aims to provide an interoperable visually lossless low-latency lightweight codec for a wide range of applications including mezzanine compression in broadcast and Pro-AV markets. This requires optimal support of a wide range of implementation technologies such as FPGAs, CPUs and GPUs. Targeted use cases are professional video links, IP transport, Ethernet transport, real-time video storage, video memory buffers, and omnidirectional video capture and rendering. In addition to the evaluation of the visual transparency of the selected technologies, a detailed analysis of the hardware and software complexity as well as the latency has been done to make sure that the new codec meets the requirements of the above-mentioned use cases. In particular, the end-to-end latency has been constrained to a maximum of 32 lines. Concerning the hardware complexity, neither encoder nor decoder should require more than 50% of an FPGA similar to Xilinx Artix 7 or 25% of an FPGA similar to Altera Cyclon 5. This process resulted in a coding scheme made of an optional color transform, a wavelet transform, the entropy coding of the highest magnitude level of groups of coefficients, and the raw inclusion of the truncated wavelet coefficients. This paper presents the details and status of the standardization process, a technical description of the future standard, and the latest performance evaluation results.
With the emergence of Ultra-High Definition video, reference frame buffers (FBs) inside HEVC-like encoders and decoders have to sustain huge bandwidth. The power consumed by these external memory accesses accounts for a significant share of the codec’s total consumption. This paper describes a solution to significantly decrease the FB’s bandwidth, making HEVC encoder more suitable for use in power-aware applications. The proposed prototype consists in integrating an embedded lightweight, low-latency and visually lossless codec at the FB interface inside HEVC in order to store each reference frame as several compressed bitstreams. As opposed to previous works, our solution compresses large picture areas (ranging from a CTU to a frame stripe) independently in order to better exploit the spatial redundancy found in the reference frame. This work investigates two data reuse schemes namely Level-C and Level-D. Our approach is made possible thanks to simplified motion estimation mechanisms further reducing the FB’s bandwidth and inducing very low quality degradation. In this work, we integrated JPEG XS, the upcoming standard for lightweight low-latency video compression, inside HEVC. In practice, the proposed implementation is based on HM 16.8 and on XSM 1.1.2 (JPEG XS Test Model). Through this paper, the architecture of our HEVC with JPEG XS-based frame buffer compression is described. Then its performance is compared to HM encoder. Compared to previous works, our prototype provides significant external memory bandwidth reduction. Depending on the reuse scheme, one can expect bandwidth and FB size reduction ranging from 50% to 83.3% without significant quality degradation.
The JPEG committee (formally, ISO/IEC SC 29 WG 01) is currently investigating a new work item on near
lossless low complexity coding for IP streaming of moving images. This article discusses the requirements
and use cases of this work item, gives some insight into the anchors that are used for the purpose of
standardization, and provides a short update on the current proposals that reached the committee.
In radiation therapy of thorax and abdomen regions, knowing how respiratory motion modifies tumor position and trajectory is crucial for accurate dose delivery to tumors while avoiding healthy tissue and organs at risk. Three types of variations are studied: motion amplitudes measured from the patient's skin surface and internal tumor trajectory, internal/external correlations and tumor trajectory baseline shift. Four male patients with lung cancer with three repeated 4D computed tomography (4DCT) scans, taken on different treatment days, were studied. Surfaces were extracted from 4DCT scans by segmentation. Motion over specific regions of interest was analyzed with respect to the motion of the tumor center of mass and correlation coefficient was computed. Tumor baseline shifts were analyzed after rigid registration based on vertebrae and surface registration. External amplitude variations were observed between fractions. Correlation coefficients of internal trajectories and external distances are greater than 0.6 in the abdomen. This correlation was observable and significant for all patients showing that the external motion is a good surrogate for internal movement on an intra-fraction basis. However for the inter-fraction case, external amplitude variations were observed between fractions and no correlation was found with the internal amplitude variations. Moreover, baseline shifts after surface registration were greater than those after vertebrae registration and the mean distance between surfaces after registration was not correlated to the magnitude of the baseline shift. These two observations show that, with the current representation of the external surface, inter-fraction variations are not detectable on the surface.
Conference Committee Involvement (2)
Applications of Digital Image Processing XLI
19 August 2018 | San Diego, California, United States
Applications of Digital Image Processing XL
7 August 2017 | San Diego, California, United States